Blind tilt assembly and method of controlling tilt ladders

ABSTRACT

A tilt assembly for a blind including a first tilt ring and a second tilt ring, both rotatable about a drive axis for supporting a pair of tilt ladders, an input connector rotatable about the drive axis and configured to receive a drive shaft for rotating a lift spool and the input connector, a secondary input mechanism rotatable about the drive axis and configured to receive the drive shaft for rotating the secondary input mechanism with the input connector, a main clutch mechanism for releasably connecting the first tilt ring to the input connector and configured to release connection at each of two opposite rotational orientations of the first tilt ring, and a secondary clutch mechanism for releasably connecting the second tilt ring to the secondary input mechanism and configured to release connection at each of two opposite rotational orientations of the second tilt ring.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 14/380,613, filed Aug. 22, 2014, entitled “Blind Tilt Assemblyand Method of Controlling Tilt Ladders”, which is the national stageapplication of International Patent Application No. PCT/EP2013/053950,filed Feb. 27, 2013, entitled “Blind Tilt Assembly and Method ofControlling Tilt Ladders,” which claims priority to European PatentApplication No. 12157142.6, filed Feb. 27, 2012, entitled “Blind TiltAssembly and Method of Controlling Tilt Ladders,” which are herebyincorporated by reference herein in their entireties.

FIELD

The present invention relates to a blind tilting assembly and a methodof controlling tilt ladders, in particular where the tilt assembly isarranged in or on the head rail of a blind, such as a Venetian blind,for mounting to an architectural opening. The tilt assembly may be usedto control cords, cables, ribbons or the like which extend therefrom andoperate upon the blind to tilt it.

BACKGROUND

A variety of different types of blind are well known for coveringarchitectural openings. Such blinds may be retracted and deployed acrossthe architectural opening, for instance by means of lift cords. Also, itis known to tilt parallel components of the blind so as to change theappearance of the blind, for example moving between an open state and aclosed state, particularly with blinds such as Venetian blinds.

It has been proposed previously to provide Venetian blinds with a doublepitch configuration such that, in an open state, pairs of slats arelocated adjacent one another, leaving double pitch openings between therespective pairs. Arrangements have also been proposed whereby one setof slats can be moved separately from another set of slats, for examplewhere alternate slats are part of one set or, alternatively, the slatsof the top half of the blind are part of one set.

U.S. Pat. No. 5,119, 868 describes a tilt assembly which is able tocontrol upper and lower sets of Venetian blinds separeately. The tiltassembly includes two rotatable drums for controlling respective tiltladders. An axial spline gear is movable within and between the twodrums by means of a horizontally movable control rod. Depending uponwhether the inner spline gear is in one or other or both of the drums,it becomes possible to vary the tilt of the upper set of slats, thelower set of slats or both sets of slats.

EP 0 887 507 A2 also relates to a tilting mechanism for a Venetian blindwhere it is possible to control a top set of slats separately from abottom set of slats. Tilt ladders for the respective sets are controlledby co axial drums in the tilt assembly. The two drums are rotatabletogether until they reach the end of an allowable rotation range. Atthat point, with one of the drums prevented from further rotation, aplanetary gear mechanism causes the other drum to reverse its directionof rotation. WO 2008/150789 describes three different arrangements forcontrolling two sets of slats.

In the first arrangement, co axial drums are provided, in the secondarrangement, parallel drums are provided and, in the third arrangement,co axial asymmetric flanges are provided. For the first arrangement, itis recognized that by attaching tilt ladders to the drums differently,it is possible to achieve a double pitch configuration, to tiltalternate slats in opposite directions or to tilt upper and lower setsof slats separately. The drums are driven by a co axial rotatable tiltrod which drives an elongate cylindrical drum driver. The drum driverhas a protrusion which extends into a crescent-shaped opening within oneof the drums such that the drum driver is able to move freely relativeto the drum between the two ends of the opening and then drive rotationof that drum. A lash spring, formed as a coil spring, grips innerportions of the two drums such that they rotate together. By restrictingrotation of the other drum, the force of the lash spring may be releasedso as to allow relative movement between the two drums.

SUMMARY

It is an object of the present invention to provide improvements to theearlier tilt assembly, in particular with regard to the user interface.

The present application recognizes the desirability of providing a tiltassembly which is driven by the same rotational control as used forlifting and lowering a blind.

According to the present invention, there is provided a tilt assemblyfor a blind including:

a first tilt element (22; 122) and a second tilt element (21; 121), forsupporting a pair of tilt ladders; an input connector (24, 27; 24′, 27;127), rotatable about a drive axis and configured to receive a driveshaft for rotating a lift spool and the input connector (24, 27; 24′,27; 127);

a main clutch mechanism (23; 123) for releasably connecting the firsttilt element (22; 122) to the input connector (24, 27; 24′, 27; 127); asecondary input mechanism (18, 17, 16, 19; 19′; 117, 118) rotatableabout the drive axis and configured to receive drive for rotating thesecondary input mechanism (18, 17, 16, 19; 19′; 117, 118) with the inputconnector (24, 27; 24′, 27; 127); and

a secondary clutch mechanism (20; 120) for releasably connecting thesecond tilt element (21; 121) to the secondary input mechanism (18, 17,16, 19; 19′; 117, 118); wherein: with rotation of the drive shaft forrotating a lift spool, the input connector (24, 27; 24′, 27; 127) isconfigured to move the first tilt element (22; 122) and then continue torotate when released by the main clutch mechanism (23; 123) and thesecondary input mechanism (18, 17, 16, 19; 117, 118) is configured torotate the second tilt element (21; 121) and then continue to rotatewhen released by the secondary clutch mechanism (20; 120).

The tilt elements may for instance be ring segments or wedges infrictional engagement with spools. Alternatively, the tilt elements maybe tilt rings in which case the invention provides a tilt assembly for ablind including:

a first tilt ring (22) and a second tilt ring (21), both rotatable abouta drive axis for supporting a pair of tilt ladders;

an input connector (24, 27), rotatable about the drive axis andconfigured to receive a drive shaft for rotating a lift spool and theinput connector (24, 27);

a main clutch mechanism (23) for releasably connecting the first tiltring (22) to the input connector (24, 27) and configured to releaseconnection at each of two opposite rotational orientations of the firsttilt ring (22);

a secondary input mechanism (18, 17, 16, 19) rotatable about the driveaxis and configured to receive drive for rotating the secondary inputmechanism (18, 17, 16, 19) with the input connector (24, 27); and

a secondary clutch mechanism (20) for releasably connecting the secondtilt ring (21) to the secondary input mechanism (23); wherein:

with rotation of the drive shaft for rotating a lift spool, the inputconnector (24, 27) is configured to rotate the first tilt ring (22) toone of the two opposite rotational orientations and then continue torotate when released by the main clutch mechanism (23) and the secondaryinput mechanism (18, 17, 16, 19) is configured to rotate the second tiltring (22) to one of the two opposite rotational orientations and thencontinue to rotate when released by the secondary clutch mechanism (20).

In this way, it becomes possible to drive both tilt rings using the samedrive as used for lifting the blind. In particular, both tilt rings areconfigured to release from the drive once they have reached either oftheir maximum rotational orientations. When the common drive is rotated,the tilt rings are first rotated together with rotation of a lift spoolfor lifting the blind, but once the tilt rings reach their rotationallimits such that the blind is fully tilted, the drive is able tocontinue to rotate to continue lifting or lowering the blind.

Optionally, the tilt assembly includes a delay mechanism (18, 17, 19)configured to receive drive from the drive shaft and to rotate freelythrough a predetermined angle before transferring drive to and rotatingthe second tilt element, e.g. ring segment (121) or tilt ring (21).

Optionally the secondary input mechanism (18, 17, 16, 19) is configuredto receive the drive shaft and includes the delay mechanism (18, 17,19), and the secondary clutch mechanism (20) may be configured torelease connection at each of two opposite rotational orientations ofthe first second ring (21).

The secondary input mechanism, secondary clutch mechanism and delaymechanism may alternatively be provided by configuring the first andsecond tilt rings to mutually engage and disengage with a delay suchthat the first tilt ring provides delayed rotational drive to thesecond. In this way, the second tilt ring is rotated at some point afterthe first tilt ring is rotated. This provides a convenient systemallowing separate control of the first and second tilt rings. Inparticular, with rotation of the common drive, the first tilt ring isrotated and then the second tilt ring is rotated. After the first tiltring reaches its predetermined maximum rotational orientation, thesecond tilt ring and the lift spool are able to continue to rotate. Oncethe second tilt ring then reaches its predetermined maximum rotationalorientation, the tilt spool is still able to rotate.

Optionally, the secondary input mechanism includes: an input part (18)configured to receive drive from and rotate with the drive shaft on thedrive axis; and a transfer part (17, 19) configured to transfer drivefrom the input part (18) to the second tilt ring (21); wherein:

the input part (18) and the transfer part (17, 19) have respectiveengagement portions (43, 37, 38) at respective circumferential regionswhich allow a predetermined range of relative rotation between thedriven part (18) and the transfer part (17, 19) before the driven part(18) drives the transfer part (17, 19).

This arrangement provides an advantageous and convenient way of delayingthe transfer drive from the common drive shaft to the second tilt ring.

Optionally, the transfer part includes:

a transfer torsion spring (17) having engagement tangs (37, 38) atrespective ends; and

a slave part (19) having at a radial periphery an axially extendingfinger (50) engaged between the engagement tangs (37, 38) of thetransfer torsion spring (17).

In this way, transfer of drive is effectively provided.

In particular, optionally the input part (18) has, at a radialperiphery, at least one axially extending prong (43) configured toengage with the engagement tangs (37, 38) of the transfer torsion spring(17) at opposite ends of the predetermined range of relative rotation.

Optionally, the tilt assembly may further include:

a stationary spring holder (16) having an outer cylindrical surfacecoaxial with the drive axis; wherein

the transfer torsion spring (17) wraps around the outer cylindricalsurface of the stationary spring holder (16) so as to releasably engagewith the stationary spring holder (16) and resist relative rotation; andthe transfer torsion spring (17) is configured to release engagementwith the stationary spring holder (16) in response to pressure of theprong (43) on an engagement tang (37, 38) such that the transfer part(17, 19) rotates with the input part (18). In this way, the transfertorsion spring grips the stationary spring holder so as to prevent anyrotation of the second tilt ring until the prong of the input part hasmoved through its predetermined range of rotation so as to release thetransfer torsion spring from the stationary spring holder.

The tilt assembly may include a housing and the stationary spring holdermay be non-rotatably mounted to the housing.

Optionally, the secondary clutch mechanism includes:

a secondary torsion spring (20) having engagement tangs (37, 38) atrespective ends;

the tilt assembly includes secondary fixed stops (75); and

the engagement tangs (37, 38) of the secondary torsion spring (20) areconfigured to be brought into engagement with respective secondary fixedstops (75) by rotation of the secondary torsion spring (20) about thedrive axis, the secondary fixed stops (75) preventing further rotationof the engagement tangs (37, 38) of the secondary torsion spring (20)and preventing further rotation of the second tilt ring (21).

This provides an advantageous arrangement for disengaging drive to thesecond tilt ring once it has reached the required predeterminedrotational orientation for the tilt of any slats.

Optionally, the secondary torsion spring wraps around an outercylindrical portion (45) of the secondary input mechanism (18, 17, 16,19) so as to releasably engage with the secondary input mechanism (18,17, 16, 19).

In a preferred embodiment, the outer cylindrical portion of thesecondary input mechanism is provided on the slave part.

Optionally, the second tilt ring includes a limit stop (55) extendingaxially from a peripheral portion of the second tilt ring (21) andengageable between the tangs (37, 38) of the secondary torsion spring(20).

Where the tilt assembly includes a housing, the base plate of thehousing may include the respective secondary fixed stops (75).

Optionally, the main clutch mechanism includes:

a main torsion spring (23) having engagement tangs (37, 38) atrespective ends;

the tilt assembly includes main fixed stops (73); and

the engagement tangs (37, 38) of the main torsion spring (23) areconfigured to be brought into engagement with respective main fixedstops (73) by rotation of the torsion spring about the drive axis, themain fixed steps (73) preventing further rotation of the engagementtangs (37, 38) of the main torsion spring (23) and preventing furtherrotation of the first tilt ring (22).

This provides an advantageous arrangement for allowing disengagement ofdrive to the first tilt ring once it has reached either of the requiredorientations for the tilt of the slats.

Optionally, the main torsion spring wraps around an outer cylindricalportion (60B) of the input connector (24, 27) so as to releasably engagewith the input connector (24, 27).

Optionally, the first tilt ring includes a limit stop (55) extendingaxially from a peripheral portion of the first tilt ring (22) andengageable between the tangs (37, 38) of the main torsion spring (23).

The releasable connection of the rotational drive to the tilt cords doesnot have to be provided by clutch mechanisms releasably connecting thedrive to the tilt rings but could be by releasably connecting the tiltrings to the tilt cords. For example, the releasable function can beprovided by use of wedges, constituting tilt elements, which arereleasably jammed into grooves of the tilt rings under gravity by havingthe tilt cords pass over them, and the wedges are released from the tiltrings by being lifted out of the grooves on engagement with stopformations, thus allowing the tilt ring to continue to rotate withoutmoving the tilt cord.

The clutches do not need to be provided by means of torsion springs butother forms of clutch are usable.

Where the tilt assembly includes a housing, the base plates may includethe respective main fixed stops.

In one embodiment the tilt assembly includes a housing (25) having abase plate (65) defining a first opening (71) for passing a pair of tiltladders to the first tilt ring (22) and second tilt ring (21) andfurther defining a second opening (72) for passing a lift cord. The tiltassembly may be provided additionally with the lift spool (12) forwinding and unwinding a lift cord and configured to connect with theinput connector (24, 27) for simultaneous rotation by a common driveshaft.

According to one particularly advantageous design, either of the tiltrings may include:

a circumferential groove (52) formed between first and second flanges(53, 54) at opposite respective axial ends of the tilt ring (21, 22);and

a member (55′) extending, at one portion of a periphery of the firstflange (53), to the second flange (54) so as to face the groove (52);wherein

the second flange (54) defines a recess (58) providing a gap between thesecond flange (54) and the member (55′); and

the member defines an aperture for receiving a fastener to extend intothe groove (52) to secure a tilt ladder in the groove (52).

In this respect, according to the present invention, there may beprovided a tilt ring for the tilt assembly of a blind and for supportinga tilt ladder, the tilt ring (21, 22) including:

a circumferential groove (52) formed between first and second flanges(53, 54) at opposite respective axial ends of the tilt ring (21, 22);and

a member (55′) extending, at one portion of a periphery of the firstflange (53), to the second flange (54) so as to face the groove (52);wherein

the second flange (54) defines a recess (58) providing a gap between thesecond flange (54) and the member (55′); and

the member defines an aperture for receiving a fastener (59) to extendinto the groove (52) to secure a tilt ladder in the groove (52).

According to the present invention, there is also provided a method ofcontrolling tilt ladders with the drive shaft of a lift spool using atilt assembly having a first tilt ring (22) and a second tilt ring (21)both rotatable about a drive axis, the method including:

providing rotatable drive from the lift spool to rotate an inputconnector (24, 27) and a secondary input mechanism (18, 17, 16, 19) ofthe tilt assembly, both being rotatable about the drive axis;

releasably connecting the first tilt ring (22) to the input connector(24, 27) and releasing connection at each of two opposite rotationalorientations of the first tilt ring (22); and releasably connecting thesecond tilt ring (21) to the secondary input mechanism (18, 17, 16, 19)and releasing connection at each of two opposite rotational orientationsof the second tilt ring (21).

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription given by way of example only, with reference to theaccompanying drawings in which:

FIG. 1 shows a Venetian blind equipped with a tilt assembly according tothe invention;

FIGS. 2A, 2B show the tilt assembly according to the invention, inexploded and assembled view respectively;

FIGS. 3A, 3B show a tilt-lift assembly according to the invention, inexploded and assembled view respectively;

FIGS. 4A-4H show the stationary spring holder of the tilt assembly;

FIGS. 5A-5J show the torsions springs of the tilt assembly;

FIGS. 6A-6F show the spring catcher of the tilt assembly;

FIGS. 7A-7F show the slave spring holder of the tilt assembly;

FIGS. 8A-8H show the tilt rings of the tilt assembly;

FIGS. 9A-9G show the master spring holder of the tilt assembly;

FIGS. 10A-10G show the housing of the tilt assembly;

FIGS. 11A-11H show the cover of the tilt assembly;

FIG. 12 shows the consecutive steps form modifying a standard laddercord into a ladder cord that is suitable for double pitch operation ofthe blind;

FIG. 13 shows a close up of the rear side of a Venetian blind, with theladder cord of FIG. 12 in mounted condition;

FIG. 14 shows the consecutive steps for modifying standard ladder cordsinto ladder cords that are suitable for duo-control operation of theblind;

FIG. 15 shows the tilt-lift assembly in frontal view;

FIG. 16 shows a further embodiment of a tilt-lift assembly according tothe invention, in exploded view;

FIG. 17 shows a further embodiment of a tilt-lift assembly according tothe invention, in exploded view; and

FIG. 18 shows the tilt-lift assembly of FIG. 17 in assembled condition.

DETAILED DESCRIPTION

FIG. 1 shows a Venetian blind 1, comprising a head rail 2, a bottom rail3, and a stack of slats 4 extending there between. The bottom rail 3 issuspended from the head rail 2 by means of at least two lift cords 5,which pass through holes in the slats 4. The slats 4 are suspended fromthe head rail 2 by means of at least two pairs of tilt ladders alsoreferred to as ladder cords 6A,B, each ladder cord 6A,B having two tiltcords one (6AF resp. 6BF) extending along the front side of the slats 4,and one (6AR resp. 6BR) extending along the rear side of the slats 4(not visible in FIG. 1) and a number of cross rungs 8A,B (also notvisible in FIG. 1) that connect the front and rear tilt cord (6AF, 6AR;6BF, 6BR) and support the individual slats 4. The blind 1 furthercomprises a drive shaft 10, which in the illustrated embodiment has asquare cross section, and that is rotatably mounted in the head rail 2.The blind 1, further comprises operating means 11 (not shown in FIG. 1)for rotating the drive shaft 10. The operating means 11 may for instancecomprise a motor, wand or ball chain, or any other drive means suitableto rotate the shaft 10. The drive shaft 10 is provided with at least twocord spools 12, for winding and unwinding the lift cords 5, and at leasttwo tilt assemblies 15, for manipulating the ladder cord pairs 6A,B, soas to change the tilt angle of the slats 4.

FIGS. 2A and 2B show the tilt assembly 15 in exploded view and assembledview. FIGS. 3A and 3B show the same tilt assembly 15 in combination witha cord spool 12, again in exploded view and assembled view.

Detailed Description of the Components

The tilt assembly 15 comprises, as seen from left to right in FIGS. 2Aand 3A, a stationary spring holder 16, a first torsion spring 17, aspring catcher 18, a slave spring holder 19, a second torsion spring 20,a second tilt ring 21, a first tilt ring 22, a third torsion spring 23,a master spring holder 24, a housing 25, a cover 26 and a cord spoolconnector 27.

In use, one pair of ladder cords 6A,B is attached to one tilt assembly15. More particularly, one ladder cord 6A is attached to the second tiltring 21 and the other ladder cord 6B is attached to the first tilt ring22. The master spring holder 24, third torsion spring 23 and housing 25together control rotation of the first tilt ring 22, whereas therotation of the second tilt ring 21 is controlled by the spring catcher18, the first and second torsion spring 17, 20 and the slave springholder 19. This will be explained in further detail below, but first theindividual components will be described in further detail.

The stationary spring holder 16 (see FIGS. 4A-4H) comprises acylindrical main body 30 that is surrounded by two radial flanges 31, 32and further comprises a bore 33. At one end of the main body 30 aU-shaped end flange 34 is provided, with an opening 35 of which thediameter is smaller than that of the bore 33 but is big enough to letthe drive shaft 10 through.

In use, the stationary spring holder 16 acts as stationary support forthe first torsion spring 17 and spring catcher 18.

The first, second and third torsion spring 17, 20, 23 all have the sameconfiguration. FIGS. 5A-5J illustrate any one of first, second, thirdtorsion springs 17, 20, 23 in a tensioned state. The ends of the springsare bend outward so as to form L-shaped tangs 37, 38 with one leg of thetang extending radially outward and another leg extending in axialdirection. Between the tangs 37, 38 a reception opening 39 is formed. Bymoving the tangs 37, 38 towards each other, i.e. by reducing thereception opening 39, the inner diameter of the springs will increase.Vice versa, by moving the tangs 37, 38 apart, i.e. by increasing thereception opening 39, the spring's inner diameter will decrease.

In use, the torsion springs 17, 20, 23 act as clutches, wherein thesecond 20 and third 23 clutch enable the drive shaft to continuerotating (for lifting lowering the slats) while the tilt rings arestationary in one of their end positions (no tilting). The first clutch17 determines together with spring catcher 18, the delay in rotation ofthe second tilt ring 21 with regard to the first tilt ring 22.

The spring catcher 18 (see FIGS. 6A-6F) has a cylindrical main body 40that is surrounded by a radial flange 41 and further comprises a bore 42with a cross section that corresponds to that of the drive shaft 10. Theradial flange 41 divides the main body 40 into a first portion 40A and asecond portion 40B. The flange 41 is provided with at least one prong 43that extends along the first portion 40A of the main body, substantiallyparallel thereto and at some distance there from. More particularly, theprong 43 is located at the same radial distance from the centre line asthe tangs 37, 38 of the torsion springs 17, 20, 23. In the illustratedembodiment, two prongs 43, 43′ are provided, but this is not essentialfor the invention.

The slave spring holder 19 (see FIGS. 7A-7F) has a cylindrical body witha stepped outer and inner diameter dividing the body in three portions:a first portion 45 of largest outer and inner diameter, a second portion46 of smaller outer and inner diameter, and a third portion 47 ofsmallest outer and inner diameter. The first portion 45 is surrounded bytwo radial flanges 48, 49 and further comprises a catch finger 50 thatprojects axially outward from its free edge, at the same radius as thetangs 37, 38 of the torsion springs and the prong 43 of the springcatcher 18.

The first and second tilt ring 22, 21 have the same configuration aseach other. FIGS. 8A-8H illustrate either of tilt rings 21 and 22. Eachtilt ring 21, 22 has a pulley shaped main body 51 with a groove 52formed between two flanges 53, 54. One of the flanges 53 is providedwith a limit stop 55, which projects outward by in the axial direction,at the same radius as the tangs 37, 38 of the torsion springs, prong 43and catch finger 50. Each tilt ring 21, 22 further comprises cord clampprovision 56 for securing a respective one of the ladder cords 6A,B inplace. In the embodiment of FIGS. 8A-8H, this cord clamp provision 56comprise barbs 57, projecting inward from the flanges 53, 54. In analternative embodiment (as best seen in FIG. 15) the flange limit stop55 may be prolonged at its other side so as to extend over the groove 52up to the other flange 54. This other flange 54 may be locally providedwith a recess 58 so as to create a gap between said flange 54 and theprolonged limit stop 55′ that provides access to the groove 52. A holemay be provided in the extended limit stop 55′ for receiving a fastener59 that after mounting of a ladder cord 6A, resp. 6B in the groove 52can be tightened to secure the cord 6A,B in place.

The master spring holder 24 (see FIGS. 9A-9G) comprises a cylindricalmain body 60, of which a first half 60A is surrounded by two flanges 61,62. At the inner side of the first half 60A, two ribs 63 are provided,extending in axial direction, at diametrically opposed positions.

The housing 25 (see FIGS. 10A-10G) comprises a rectangular base plate 65which near its short sides is provided with two side walls 66, 67. Thefirst side wall 66 has a U-shaped recess 68 and is further at itsoutward facing side provided with two recesses 69. The second side wall67 has a circular opening 70 and is at its outward facing side providedwith similar recesses 69 as the first side wall. A substantiallyC-shaped first opening 71 is provided in the base plate 65, somewhatnearer to the second side wall 67 than to the first side wall 66. A muchsmaller second opening 72 is provided in the base plate portion that issurrounded by the C-shaped opening 71. Further, two stop formations 73,75 are provided on the base plate 65 on either side of the first opening71 with the first stop formation 73 adjoining the second side wall 67and the second stop formation 75 being located right across the firstopening 71, at some distance from the first side wall 66. A thirdopening 76 is provided, that extends through the first stop formation 73and the second side wall 67.

The cover 26 (see FIGS. 11A-11H) comprise a rectangular top plate 77which near its short sides is provided with two click fingers 78, 79.

The cord spool connector 27 (see FIGS. 3A and 3B) comprises acylindrical main body 80, which at one end is surrounded by a flange 81.The main body 80 is provided with two diametrically opposed slots 82,extending in axial direction up to the flange 81. The flange 81 is atits other side provided with suitable coupling means (not visible), e.g.two or more click fingers for securing the connector 27 to the cordspool 12 in a non-rotatable way.

The cord spool 12 (see FIGS. 3A and 3B) may for instance be configuredas described in applicant's international application PCT/EP2011/001656.

Assembled Condition

To assemble the tilt assembly 15, the first torsion spring 17 is mountedon the stationary spring holder 16 between its flanges 31, 32. Thesecond torsion spring 20 is mounted on the first portion 45 of the slavespring holder 19, between its flanges 48, 49. The third torsion spring23 is mounted on the first half 60A of the master spring holder 24,between its flanges 61, 62. The outer diameter of the respectivecomponents 16, 45, 60A is slightly larger than the inner diameter of theuntensioned torsion springs 17, 20, 23. Thus, during mounting the tangs37, 38 will move towards each thereby causing the springs' diameter toincrease and causing the springs to become tensioned. Thanks to thistension, the springs will be clamped around the components 16, 45, 60Awith some clamping force, which prevents the torsion springs 17, 20, 23from rotating relative to their respective components 16, 45, 60A.

Next, the first portion 40A of the spring catcher 18 is inserted in thestationary spring holder 16 and the second portion 40B is inserted inthe slave spring holder 19. The relative orientation of the respectivecomponents is such that the catch finger 50 of the slave spring holder19 is received in the reception opening 39 between the tangs 37, 38 ofthe first torsion spring 17 and the or each prong 43 of the springcatcher 18 lies outside said reception opening 39.

Next, the second tilt ring 21 is mounted on the second portion 46 of theslave spring holder 19 with its limit stop 55 extending in the receptionopening 39 between the tangs 37, 38 of the second torsion spring 20, andthe first tilt ring 22 is mounted on the second half 60B of the masterspring holder 24 with its limit stop 55 extending in the receptionopening 39 between the tangs 37, 38 of the third torsion spring 23.

Next, the third portion 47 of the slave spring holder 19 is inserted inthe second half 60B of the master spring holder 24.

Meanwhile, a pair of ladder cords 6A, 6B is inserted into the housing 25through the first opening 71, and a lift cord 5 is inserted into thehousing 25 through the second opening 72 and guided out off the housing25 via the third opening 76.

Next, the ladder cords 6A, 6B are mounted around the first 22 and second21 tilt ring and secured in place by means of the cord clamp provision56 or 59. As will be explained below in further detail, there areseveral ways to mount the ladder cords 6A, 6B with respect to the tiltrings 21, 22 and this will determine the ways in which the slats can betilted.

The sub-assembly resulting from the foregoing assembly steps is loweredinto the housing 25 such that the U-shaped end flange 34 of thestationary spring holder 16 is received in the U-shaped slot 68 in thefirst side wall 66, thereby ensuring that the spring holder 16 is heldstationary in the housing 25.

Next, the main body 80 of the cord spool connector 27 is insertedthrough the opening 70 in the second side wall 67 of the housing 25 andinto the first half 60A of the master spring holder 24, where the slots82 engage the ribs 63 to establish a non-rotatable connection betweenthe cord spool connector 27 and the master spring holder 24. The cordspool connector 27 itself is rotatably supported in the opening 70.

Next, the cord spool 12 is snap fitted onto the coupling means of thecord spool connector 27 so as to establish a non-rotatable connectionthere between.

Next, the lift cord 5 which exits the housing 25 through the thirdopening 76 is guided along what in FIG. 1 would be the rear side of thecord spool 12, and is attached to the end of the cord spool 12 thatfaces away from the tilt assembly 15. The assembly is subsequentlymounted onto the drive shaft 10.

Finally, the housing 25 is closed by snapfitting the cover 26 in place,wherein the barb shaped end portions of the click fingers 78, 79 lockbehind the recesses 69 in the first and second side wall 66, 67. Thecover 26 helps to keep the ladder cords 6A, 6B into the grooves 52 ofthe tilt rings 21, 22 and thus prevents the cords 6A, 6B from falling ofthe tilt rings or becoming tangled or misaligned.

Operation of the Tilt Assembly

In an initial position (when the blind is fully retracted) the firsttangs 37 of the second and third torsion spring 20, 23 respectively abutthe right hand side (as seen in FIG. 2A) of the first and second stopformation 73, 75. The limit stop 55 of the first and second tilt ring22, 21 abut said first tangs 37. Accordingly, both tilt rings 21, 22 liein a first end position in which these rings are prevented from rotatingin clockwise direction (as indicated by arrow R in FIG. 2A). Theposition of the tangs 37, 38 of the first torsion spring 17 may vary (nofixed position). However, the prong 43 of the spring catcher 18 will liein abutment with the second tang 38 of the first torsion spring 17.

When the drive shaft 10 is rotated counter clockwise (in the directionof Arrow T in FIG. 2A), the cord spool 12 will start to rotate counterclockwise and with that the master spring holder 24 (by means of thecord spool connector 27 which non-rotatably connects the master springholder 24 to the cord spool 12). The third torsion spring 23 rotateswith the master spring holder 24, taking along between its tangs 37, 38the limit stop 55 of the first tilt ring 22 and with that, the firsttilt ring 22 itself. Since the spring catcher 18 is non-rotatablyconnected to the drive shaft 10 via its square shaped bore, the rotationof the drive shaft 10 will cause the spring catcher 18 to rotate incounter clock wise direction as well, causing its prong 43 to move awayfrom the second tang 38 of the first torsion spring 17.

As the drive shaft is further rotated in counterclockwise direction, theprong 43 will come in abutment with the first tang 37 of the firsttorsion spring 17 and upon further rotation will urge said first tang 37towards the second tang 38, causing the first spring 17 to open (i.e.its inner diameter to increase). Accordingly, the first torsion spring17 will start to rotate with respect to the stationary spring holder 16(the latter being prevented from rotating by the housing 25). As thefirst torsion spring 17 rotates it will take along the slave springholder 19 via the catch finger 50 which is caught between the tangs 37,38. Since the second torsion spring 20 is clamped onto the slave springholder 19 it will rotate along, taking along between its tangs 37, 38the limit stop 55 and with that the second tilt ring 21.

Thus, with the tilt assembly according to the embodiment of theinvention, the first tilt ring 22 will start to rotate first. The secondtilt ring 21 will follow with a certain delay. The duration of thisdelay is determined by the extent to which the prong 43 can freelyrotate before hitting against one of the tangs 38, 37, causing the firstspring 17 to open and start rotating, and with that the second tilt ring21.

Meanwhile, when the first tilt ring 22 has been rotated over about 180°in counter clockwise direction, the second tang 38 of the third torsionspring 23 and the limit stop 55 of the first tilt ring 22 will come intoabutment with the left hand side of the first stop formation 73. As thedrive shaft 10 is rotated further it will cause the second tang 38 to beurged towards the first tang 37, thereby causing the third torsionspring 23 to open, thereby allowing the master spring holder 24 torotate freely, while the third torsion spring 23 and first tilt ring 22remain stationary in said second end position in which they areprevented from rotating further in anti clock wise direction. A similareffect occurs when the second tang 38 of the second torsion spring 20and the limit stop 55 of the second tilt ring 21 abut the left hand sideof the second stop formation 75. Upon further rotation of the driveshaft 10, the tang 38 is urged toward the first tang 37 causing thesecond torsion spring 20 to open, thereby releasing its grip on theslave spring holder 19 and allowing the spring catcher 18, first torsionspring 17 and slave spring holder 19 to rotate freely, while the secondtorsion spring 20 and the second tilt ring 21 remain stationary in theirsecond end position.

At this point in time, the tilt action of the tilt assembly is completedand the drive shaft 10 can now be rotated counter clockwise as long asdesired to unwind the lift cord (and lower the slats).

When a user subsequently rotates the drive shaft 10 in clock wisedirection (as indicated by arrow R in FIG. 2A) the same sequence ofmotions occurs, but now in clockwise direction. That is, the masterspring holder 24 will start to rotate in clockwise direction, therebyrelieving the force on the tang 37 of the third torsion spring 23allowing the spring 23 to close and start rotating with the masterspring holder 24, taking along the first tilt ring 22.

Meanwhile, the spring catcher 18 will rotate along with the drive shaft10 in clock wise direction, causing prong 43 to move away from the firsttang 37 of the first spring 17, thereby allowing the spring to close andstop rotating, causing the slave spring holder 19 to stop rotating aswell. The second tilt ring 21 remains stationary in its aforementionedsecond end position.

When the shaft 10 is rotated further in clockwise direction, the prong43 of the spring catcher 18 will abut against the second tang 38 of thefirst torsion spring 17, causing the spring to open and rotate alongwith the spring catcher 18, thereby rotating the slave spring holder 19along and with that, the second torsion spring 20 which will in turnrotate the second tilt ring 21 along.

Meanwhile, when the first tilt ring 22 has been rotated over about 180°in clock wise direction the first tang 37 of the third torsion spring 23and the limit stop 55 of the first tilt ring 22 will come into abutmentwith the right hand side of the first stop formation 73. As the driveshaft 10 is rotated further it will cause the first tang 37 to be urgedtowards the first tang 37, causing the spring 23 to open, therebyallowing the master spring holder 24 to rotate freely, while the thirdtorsion spring 23 and first tilt ring 22 remain stationary in the firstend position in which they cannot rotate further in clock wisedirection.

Similarly, when the first tang 37 of the second torsion spring 20 andthe limit stop 55 of the second tilt ring 21 abut the right hand side ofthe second stop formation 75, the tang 37 will be urged toward thesecond tang 38 causing the second torsion spring 20 to open, therebyreleasing the slave spring holder 19 and allow said slave spring holder19 to continue to rotate freely, with the spring catcher 18 and thefirst torsion spring 17, while the second torsion spring 20 and thesecond tilt ring 21 remain stationary in their first end position.

At this point in time, the tilt action of the tilt assembly 15 iscompleted and the drive shaft 10 can be rotated clockwise as long asdesired to wind up the lift cord 5 (thereby raising the slats 4).

The rotation sequence of the tilt rings 21, 22 can be used to tilt theslats 4 in several ways, depending on how the ladder cords 6A, 6B arecoupled to said tilt rings 21, 22.

Double Pitch Operation

For operating the blind in double pitch-mode the rear tilt cords 6AR,6BR of the pair of ladder cords 6A, 6B need to be cross wise connectedto the first and second tilt rings 22, 21, which means that therespective front tilt cords 6AF, 6BF are operatively connected to thefirst and second tilt ring 22, 21 while the respective rear tilt cords6AR, 6BR are operatively connected to the second and first tilt ring 21,22. In an alternative embodiment, the front tilt cords could becrosswise connected to the tilt rings.

According to a preferred embodiment, this can be simply realized bytaking a double pitch ladder cord 6. First, the two cross rungs 8extending halfway along the cord 6 are cut away (see FIG. 12). Next, theupper half of the cord (which in FIG. 12 has been given another greyshade, for clarity sake) is twisted around its longitudinal axis over180° . Next, the upper half is folded on top of the bottom half. Next,the part 6A of the folded cord that corresponds to the upper half isslung around the second tilt ring 21 and the part 6B of the folded cordthat corresponds to the lower half is slung around the first tilt ring22, such that the crossing point 7 of the tilt cords lies somewhere atthe rear side of the tilt rings 21, 22 as schematically shown in FIG. 12and more truthfully depicted in FIG. 13.

Preferably, the cords 6A, 6B are secured to the first and second tiltring 22, 21 in such a way that when the limit stops 55 of both tiltrings 21, 22 are located exactly halfway their first and second endpositions, the cross rungs 8A,B extend substantially horizontally andthe ladder cords 6A,B are shifted with respect to each other over halfthe pitch height, so that the cross rungs 8A of the first cord 6A extendhalfway the cross rungs 8B of the second cord 6B, as seen in verticaldirection. The cords 6A,B can be secured in this position by means ofthe cord clamp provisions 56, 59.

It is noted that the abovementioned situation would not occur during‘normal’ operation of the drive shaft 10 because the rotation of thesecond tilt ring 21 always lags behind, as explained before. Thus, thelimit stops 55 of the first and second tilt ring 22, 21 will only becomealigned in their first and second end positions, not in someintermediate position. However, it is possible to manipulate the tiltassembly 15 in such way that the limit stops 55 will become alignedhalfway their end positions. This will be explained later (see “standardVenetian blind operation”).

The double pitch operation of the blind 1 will now be explained,starting from the fully retracted position, wherein the lift cords 5will be wound onto the cord spools 12 and the first and second tiltrings 22, 21 will be in their first end position (with both limit stops55 abutting the right hand side of the first and second stop formation73, 75). In this first end position, the cross rungs 8A,B will beslanted downward from the rear to the front of the blind 1. However,since the bottom rail 3 is fully lifted, all slats 4 will be supportedso as to extend substantially horizontally.

When the drive shaft 10 is rotated counter clockwise, the lift cords 5will be lowered, causing the upper most slat 4B to be singled out fromthe stack. Being no longer supported by the bottom rail 3, the slat 4Bwill adopt the aforementioned downward slanted orientation of the uppermost cross rung 8B.

During the first phase of operation, the first tilt ring 22 will rotatecounter clockwise causing the front tilt cord 6BF of the second laddercord 6B to be raised and the rear tilt cord 6AR of the first ladder cord6A to be lowered, while the second tilt ring 21 and associated tiltcords (6AF, 6BR) remain stationary. As a result, the front side of thecross rungs 8B of the second ladder cord 6B will be lifted, while therear side of the cross rungs 8A of the first ladder cord 6A will belowered. Consequently, the orientation of the cross rungs 8A,B willchange from a downward slanted orientation to a more horizontalorientation. The spacing between the cross rungs 8A,B will increase.

During a second phase of operation, the second tilt ring 21 will startrotating as well, causing the front tilt cord 6AF of the first laddercord 6A to be raised and the rear tilt cord 6BR of the second laddercord 6B to be lowered. This causes the cross rungs 8A,B to be tilted inthe same manner as during the first phase, but at a double rate, due tothe combined effect of the first and second tilt rings 22, 21. Thespacing between the cross rungs 8A,B, will not change during this phase.

During a third phase of operation, the first tilt ring 22 will havereached its second end position, while the second tilt ring 21 is stillrotating. Thus, the front tilt cord 6AF will be raised further, and therear tilt cord 6BR will be lowered further while the other tilt cordsremain stationary. This causes the rear side of the cross rungs 8B to belowered, and the front side of the cross rungs 8A to be lifted.Accordingly, the cross rungs 8A,B are further tilted and the spacingbetween the cross rungs 8A,B decreases, thereby undoing the increase inspacing during the first phase.

Thus, at the end of the third phase, both tilt rings 21, 22 will havereached their second end position, the slats 4A,B are maximally tiltedclosed so as to slant downward from the front to the rear side of theblind 1 and the cross rungs 8A of the first ladder cords 6A will extendabout halfway the cross rungs 8B of the second ladder cord 6B, as seenin vertical direction.

The blind 1 may now be lowered further, as far as desired, by continuingto rotate the drive shaft 10 in counter clock wise direction. No furthertilting will take place. The slats 4A,B will be lowered in theaforementioned tilted closed orientation.

When the blind 1 has been lowered to a desired position, a user mayreverse the rotation direction of the drive shaft 10 to open the slatsof the blind 1. This will initiate a fourth phase of operation, in whichthe lift cord 5 starts to be wound on the cord spool 12, and the firsttilt ring 22 will start rotating in clock wise direction. This willcause the front tilt cord 6BF of the second ladder cord 6B to be loweredand the rear tilt cord 6AR of the first ladder cord 6A to be lifted,while the other tilt cords (6AF, 6BR) remain stationary. As a result,the front side of the cross rungs 8B/slats 4B will be lowered and thusapproach the stationary front side of the cross rungs 8A/slats 4A.Likewise, the rear side of the cross rungs 8A/slats 4A will be lifted,thereby approaching the stationary rear side of the cross rungs 8B/slats4B. Thus, during this fourth phase, the slats 4A,B will be tilted opentowards a more horizontal position, and at the same time, the slats 4A,Bwill approach each other in pairs.

Typically, the dimensioning of the tilt assembly 15 will be such that atthe end of the fourth phase the slats 4A,B of each pair will have fullyapproached each other. However, the slats may not have been fully tiltedopen (horizontal) yet. In such case, a user may continue to rotate thedrive shaft 10 in clockwise direction, thereby entering a fifth phase ofoperation in which the second tilt ring 21 starts to rotate as well.During this phase, both front tilt cords 6AF, 6BF will be lowered andboth rear tilt cord 6AR, 6BR will be raised, causing the cross rungs8A,B and slats 4A,B to be tilted open further, at double rate, withoutaffecting the spacing between the cross rungs 8A,B and slats 4A,B.

During a sixth phase of operation, the user may continue to rotate thedrive shaft 10. In this phase, the first tilt ring 22 will have reachedits first end position will have stopped rotating. The second tilt ring21 will still rotate, causing the slats 4A,B to move apart and tilt to amaximum closed position, wherein the slats are tilted downward from therear to the front side. Upon further rotation of the drive shaft 10 nofurther tilting will take place, but the lift cords will be wound ontothe cord spools 12 and the slats 4A,B will be raised.

It may be noted that the delay of the rotation of the second tilt ring21 with respect to the first tilt ring 22 is determined by the freestroke over which prong 43 can rotate before hitting one of the tangs37, 38, which will depend on the “width” of the prong 43 or, if twoprongs 43 are provided, their location along the spring catcher 18, andon the location of the tangs. It is possible to delay rotation of thesecond tilt ring till the first tilt ring has already reached an endposition. In such case, the first and second tilt ring will never rotatetogether as described in the second and fifth phase of operation.Obviously, this will also have an effect on the exact movement of theslats.

Standard Venetian Blind Operation

Instead of tilting the slats open in double-pitch mode, as describedabove, the slats can also be tilted open with a normal (single) pitch.This situation occurs when the limit stops 50 of the first and secondtilt ring 22, 21 are aligned halfway the first and second end position.

To bring the tilt rings 21, 22 in such a position, the second phase ofoperation is changed. Instead of allowing the second tilt ring 21 toreach its second end position, counter clock rotation of the drive shaft10 is stopped when the second tilt ring 21 reaches a position in whichits limit stop 50 extends halfway the first and second end position.

Next, the drive shaft 10 is rotated clock wise. As a consequence, theprong 43 of the spring catcher 18 will no longer urge the first tang 37of the first torsion spring 17 towards the second tang 38. As a resultthe first spring will close and stop rotating around the stationaryspring holder 16. Accordingly, the slave spring holder 19 and the secondtorsion spring 20 will stop rotating as well and the second tilt ring 21will remain stationary at the aforementioned position. However, theclockwise rotation of the drive shaft 10 will cause the first tilt ring22, which is in its second end position, to start rotating. Rotation ofthe drive shaft 10 is stopped when the limit stop 50 of the first tiltring 22 is aligned with the limit stop 50 of the second tilt ring 21. Inthis position, the slats 4A,B will extend substantially horizontally andat a normal pitch.

Duo-Control Operation

For the duo control operation, a first ladder cord 6A is provided forsupporting the slats 4L in the lower part of the blind 1 and a secondladder cord 6B is provided that supports the slats 4U in the upper partof the blind.

The first ladder cord 6A can be prepared by taking a standard laddercord and by cutting away the cross rungs 8A in the upper half of thecord so that the number of remaining cross rungs 8A in the lower half ofthe cord corresponds to the number of slats 4L in the lower half of theblind (see FIG. 14).

The second ladder cord 6B may be a standard ladder cord with a lengthand number of cross rungs 8B that correspond to the number of slats 4Uin the upper half of the blind.

The first ladder cord 6A is mounted on and secured to the second tiltring 21, and the second ladder cord 6B is mounted on and secured to thefirst tilt ring 22, such that the cross rungs 8A,B of the respectiveladder cords extend substantially horizontally when the limit stops 50of the first and second tilt ring 22, 21 extend halfway their first andsecond end position.

The duo-control operation of the blind 1 will be explained starting fromthe fully retracted position, wherein the first and second tilt rings22, 21 are in the first end position. In this first end position, thecross rungs 8A,B will be slanted downward from the rear to the front ofthe blind 1, but because the bottom rail 3 is fully lifted, all slats 4will be supported so as to extend substantially horizontally.

When the drive shaft 10 is rotated counter clockwise, the lift cord 5will start to unwind from the cord spool 12 and the first tilt ring 22will rotate counter clockwise from its first end position to its secondend position. This rotation causes the cross rungs 8B/upper slats 4U totilt from the abovementioned initial orientation to a tilted closedorientation in which the slats 4U are slanted downward in the oppositedirection, i.e. from the front to the rear.

Somewhere during the rotation of the first tilt ring 22, the second tiltring 21 will start to rotate as well, causing the cross rungs 8A/lowerslats 4L to tilt to the same closed position as the cross rungs 8B/upperslats 4U.

Further counter clockwise rotation of the drive shaft 10 will cause thelift cords 5 to unwind further, thereby lowering the upper slats 4U andsubsequently the lower slats 4L.

When the blind 1 has been lowered to a desired position, the user maystart to rotate the drive shaft 10 in clock wise direction. This willcause the lift cord 5 to be wound onto the cord spool 12, therebyraising the lowermost slats. At the same time, the first tilt ring 22will start to rotate in clockwise direction, causing the cross rungs8B/upper slats 4U to tilt open towards a horizontal position.

By continuing to rotate the drive shaft 10 in clock wise direction, thesecond tilt ring 21 will start to rotate as well, causing the lowerslats 4L to tilt open towards a horizontal position. At the same time,the upper slats 4U will tilt further until the first tilt ring 22reaches its first end position. In said position, the upper slats 4Uwill have been tilted closed, i.e. slanted downward from the rear to thefront of the blind.

Further clockwise rotation of the drive shaft 10 will cause the secondtilt ring 21 to reach its first end position as well, in which the lowerslats 4L will have the same tilted closed orientation as the upper slats4U.

Further clockwise rotation of the drive shaft will cause the slats to beretracted.

FIG. 16 shows another embodiment of a tilt assembly according to theinvention. This tilt assembly 15′ includes a first tilt element (firsttilt ring 22) a second tilt element (second tilt ring 21), a main clutchmechanism (torsion spring 23) and a secondary clutch mechanism (torsionspring 20) that are substantially similar to the previous embodiment.The tilt assembly differs over the previous embodiment in that itincludes a modified input connector and a modified secondary inputmechanism.

The input connector includes a cord spool connector 27 and a masterspring holder 24. The cord spool connector 27 is similar to the onedescribed in relation to the previous embodiment. It comprises acylindrical main body 80 that at one end is provided with a flange 81.The main body is provided with two slots 82 extending in axial directionat diametrically opposed positions. The flange 81 is at its other sideprovided with two click fingers 83.

The master spring holder 24′ comprises a cylindrical main body 60 with afirst portion 60A that is surrounded by two flanges 61, 62 and a secondportion 60B that is provided with a master catch 64. This master catch64 projects axially outward from a free edge of said second portion 60Balong a portion of its circumference. The first half 60A is at its innerside provided with two ribs (not visible) extending in axial directionat diametrically opposed positions.

The secondary input mechanism includes a slave spring holder 19′. Theslave spring holder 19′ comprises a first cylindrical portion 45′ thatis surrounded by two radial flanges 48′, 49′ and a second cylindricalportion 46′ that is of smaller diameter than the first portion 45′. Thefirst cylindrical portion 45′ is provided with a slave catch 50′ thatprojects axially outward from the transition between the first andsecond cylindrical portion along a portion of the outer circumference ofthe second cylindrical portion 46′.

In assembled condition, torsion spring 23 is mounted on the masterspring holder 24′, between the flanges 61, 62 and torsion spring 20 ismounted on the slave spring holder 19′ between the flanges 48′, 49′.Furthermore, the first tilt ring 22 is mounted on the second portion 60Bof the master spring holder 24′ and the second tilt ring 21 is mountedon the first cylindrical portion 45′ of the slave spring holder 19′ thatextends between flange 48′ and the second cylindrical portion 46′. Thefirst and second tilt ring 22, 21 are mounted such that their respectivelimit stops 55 extend between the tangs of torsion spring 23,respectively 20. Next, the second cylindrical portion 46′ of the slavespring holder 19 ‘is inserted in the second portion 60B of the masterspring holder 24’. This subassembly is mounted in the housing 25 suchthat both the master spring holder 24′ and the slave spring holder 19′are supported in the housing 25 for rotation. Next the cord spoolconnector 27 is non-rotatably connected to the cord spool 12 via clickfingers 83, and the master spring holder 24 is non-rotatably connectedto the cord spool connector 27 via its ribs being received in the slots82.

When the cord spool 12 is rotated by the drive shaft, the inputconnector 27 and master spring holder 24′ will be rotated as well. Theslave spring holder 19′ may initially remain stationary until the mastercatch 64 engages the slave catch 50′. This will cause the slave springholder 19′ to be rotated by the master spring holder 24′. The torsionsprings 23, 20 are clamped around the master and slave spring holderrespectively, and therefore will rotate together therewith, draggingalong the first and second tilt rings 22, 21 (via the limit stops 55that are caught between the tangs 37, 38 of the springs 23, 20). As withthe previous embodiment, when a limit stop 55 of the first or secondtilt ring 22, 21 comes into abutment with a stop formation 73, 75, theassociated torsion spring 23, 20 will be opened thereby releasing thetilt ring from the input connector/master spring holder 24′ and/or fromthe secondary input mechanism/the slave spring holder 19′. As aconsequence, the master spring holder 24 and slave spring holder 19′ maycontinue to rotate while the tilt rings 22, 21 remain stationary intheir end position.

If the rotation direction of the drive shaft is reversed, the masterspring holder 24′ will start rotating in the opposite direction therebyrelieving the force on the tang 37 of the torsion spring 23. As aconsequence, the spring 23 may close and start rotating with the masterspring holder 24′ dragging the first tilt ring 22 along. When the mastercatch 64 on the master spring holder 24′ engages the slave catch 50′ onthe slave spring holder 19′ the latter will start rotating in oppositedirection as well, allowing the torsion spring 20 to close and dragalong the second tilt ring 21

It will be appreciated that the geometry of the master catch 64 and theslave catch 50′ determines the angle over which the master spring holder24′ can rotate before it engages the slave spring holder 19′ and thusdetermines the delay between rotation of the first and second tilt rings22, 21. Depending on the design of the catches 64, 50′, in particulartheir angular extent in circumferential direction, the delay may rangefrom virtually no delay (the catches 64 and 50′ together span the entirecircumference of the master and slave spring holder) to a maximum delayof almost one full revolution of the master spring holder 24′ (eachcatch 64, 50′ has an angular extent of a few degrees only).

FIGS. 17 and 18 show another embodiment of a tilt-lift assemblyaccording to the invention, in exploded view and assembled conditionrespectively. The tilt-lift assembly comprises a cord spool 112 and atilt assembly 115. The cord spool may be similar to the one shown inFIGS. 1, 3A and/or 15. The tilt assembly 115 includes a first tiltelement, more particularly a first ring segment 122, and a second tiltelement, more particularly a second ring segment 121 for supporting apair of tilt ladders (not shown). The tilt assembly 115 further includesan input connector 127 configured to receive and rotate with a driveshaft (not shown) that in use also drives the cord spool 112. The tiltassembly 115 further includes a main clutch mechanism, in particular amain spool 123 for releasably connecting the first tilt element 122 tothe input connecter 127, a secondary input mechanism 118, 117 configuredto receive drive so as to rotate with the input connector 127; and asecondary clutch mechanism, in particularly a secondary spool 120 forreleasably connecting the second tilt element 121 to the secondary inputmechanism 118, 117.

The first and second ring segments 122, 121 can be brought intofrictional engagement with an outer periphery of the main spool 123 andthe secondary spool 120 respectively. The outer periphery of said spools123, 120 may thereto be provided with a groove 136, preferably a taperedgroove with slanting side walls 137, 138. The first and second ringsegments 122, 121 may likewise be tapered, so as to form wedges withslanted side walls 153, 154. In assembled condition, these wedges orring segments 122, 121 can be fitted at least partly in the respectivegrooves 136, with their sidewalls 153, 154 frictionally engaging theside walls 137, 138 of the grooves 136. Each respective side wall 153,154 of the ring segments 122, 121 may be provided with dedicatedfrictional surfaces, which may be a single continuous surface or severaldiscrete surfaces, e.g. provided towards the respective ends of the ringsegments 122, 121.

The secondary input mechanism includes a first catch 118 on the mainspool 123 facing the secondary spool 120, and a second catch 117 on thesecondary spool 120 facing the main spool 123. The first and secondcatches 117, 118 are arranged such that the first catch 118 will engagethe second catch 117 when the main spool 123 is rotated relative to thesecondary spool 120. In engaged condition, the secondary spool 120 willrotate together with the main spool 123.

The tilt assembly 115 further includes first and second stop formations173A,B, 175A,B provided adjacent the outer circumference of the mainspool 123 and secondary spool 120 respectively, to limit rotation of thefirst and second ring segment 122, 121 respectively in clockwise andcounterclockwise direction. In the illustrated embodiment these stopformations 173A,B, 175 A,B are integrally formed with the housing 125 ofthe tilt assembly 115. In an alternative embodiment, the stop formations173A,B, 175A,B may be formed as separate parts that can be releasablyconnected to the housing 125, for instance through snap fit action.Advantageously, a selection of different stop formations 173A,B, 175A,Bmay be provided, with different sizes, in particular with differentangular extents along the circumference of the spools 123, 120. In thisway, the maximum tilt angle of the tilt assembly can be readily variedby interchanging the stop formations. Accordingly, the tilt assembly 115can be readily adapted for use with different blinds, e.g. with slats ofdifferent widths requiring different maximum tilt angles.

In assembled condition, illustrated in FIG. 18, the main spool 123 ismounted onto the input connector 127 in a non rotatable way and thesecondary spool 120 is mounted on the support body 130 in a rotatableway. The support body 130 is with one end connected to the support bodyholder 116 in a non-rotatable way and with its other end connected tothe input connector 127 so as to support the input connector 127 in arotatable way. This subassembly is mounted into the housing 125, withthe support body holder 116 being stationary and the input connector 127being supported for rotation. A pair of tilt ladders 6A, 6B is securedto the first and second ring segment 122, 121 in any suitable wayaccording to one of the previously described configurations depending onthe desired tilt configuration of the slats, i.e. double pitchoperation, duo-control operation, etc. The first and second ring segment122, 121 are subsequently fitted into the respective grooves 136 of themain and secondary spool 123, 120. Next, the cord spool 112 is connectedto the input connector 127 in a non-rotatable way, a lift cord 5 is withone end secured to the cord spool 112, and the housing 125 may be closedwith a cover 126.

The tilt assembly 115 operates as follows. When the drive shaft isrotated clockwise or counter clockwise, the cord spool 112, inputconnector 127 and main spool 123 will be rotated as well. Depending onthe design of the first and second catches 118, 117 the secondary spool120 may initially remain stationary, until the first catch 118 engagesthe second catch 117. This will cause the secondary spool 120 to startrotating together with the main spool 123. The first and second ringsegment 122, 121 will be in frictional engagement with the respectivespools 123, 120. This frictional engagement may be enhanced by theweight of the slats hanging from the tilt ladders 6A,6B. Accordingly,the first and second ring segment 122, 121 will rotate together with therespective spools 123, 120. When a ring segment 122, 121 abuts one ofthe associated stop formations 173A,B, 175A,B, further rotation of saidring segment will be prevented and further tilting of the associatedslats will be halted. As rotation of the associated spool is continued,said ring segment may be slightly lifted from the groove 136 and startto slip with regard to the spool. By overcoming the frictionalengagement force, the spool 123, 120 may be continued to be rotatedwhile the ring segment remains in its end position. If the rotationdirection of the drive shaft is reversed, the main spool 123 will startrotating in the opposite direction. The first ring segment 122 will nolonger be lifted by the stop formation 173A,B and will be urged backinto frictional engagement with the main spool 123 through gravity.Accordingly, the first ring segment 122 will start rotating togetherwith the main spool. When the first catch 118 on the main spool 123engages the second catch 117 on the secondary spool 120, the latter willstart rotating in opposite direction as well, taking along the secondring segment 121 through frictional engagement.

It will be appreciated that the frictional engagement between therespective ring segments 122, 121 and spools 123, 120 functions as aclutch mechanism that allows continued rotation of said spools, thedrive shaft and the cord spool 112 when the tilt elements (first andsecond ring segments 122, 121) have reached an end position and tiltingof the slats is halted. As a consequence, it becomes possible to driveboth tilt elements 122, 121 using the same drive as used for lifting andlowering the blind.

Since the functioning of this clutch mechanism is based on gravity andfriction, this tilt assembly 115 may work best with relatively large,i.e. heavy blinds. Thanks to the absence of springs, this tilt assembly115 may be very cost effective.

It will further be appreciated that the secondary input mechanism 117,118 may include a delay mechanism. Depending on the geometry of thecatches 117, 118, in particular their angular extent as seen incircumferential direction of the spools, the main spool 123 will rotatethrough a predetermined angle before the first catch 118 engages thesecond catch 117. This predetermined angle may have any value betweenvirtually zero and approx. 355° . When the predetermined angle isvirtually zero there will be no delay. When the predetermined angle isapprox. 355° the delay will be maximum, i.e. almost a full revolution ofthe main spool 123.

According to an optional aspect of the invention, the stationary supportbody 130 may be provided with a conical outer surface as illustrated inFIG. 17. The secondary spool 120 can be press-fitted onto the largediameter end of the support body, thereby locking said spool 120 againstunintentional rotation. Such unintentional rotation may for instanceoccur under influence of the weight of the slats or through frictionalcontact between the spools 123, 120. The first catch 118 on the mainspool may be provided with chamfered edges. When the first catch 118approaches the second catch 117, the chamfered edge will cause thesecondary spool 120 to be displaced axially, away from the main spool,to a portion of the support body 130 of smaller diameter, where thesecondary spool 120 can rotate freely. A spring 129 may be provided atthe other side of the secondary spool 120, as illustrated in FIG. 17, tobias the secondary spool 120 towards the main spool 123 and ensure thatthe first catch 18 remains engaged with the second catch 17.

What is claimed is:
 1. A method of controlling a tilt ladder with adrive shaft using a tilt assembly having a first tilt element and asecond tilt element both rotatable about a drive axis, the methodcomprising: providing rotatable drive from the drive shaft to rotate aninput connector and an input mechanism of the tilt assembly, both beingrotatable about the drive axis; releasably engaging the first tiltelement to the input connector and releasing engagement at each of twoopposite rotational orientations of the first tilt element; andreleasably engaging the second tilt element to the input mechanism andreleasing engagement at each of two opposite rotational orientations ofthe second tilt element.
 2. The method of claim 1, further comprisingdelaying rotation of the second tilt element until after the first tiltelement has begun to rotate.
 3. The method of claim 1, whereinreleasably engaging the second tilt element to the input mechanismcomprises: engaging an input part of the input mechanism to the driveshaft; selectively engaging a transfer part of the input mechanism tothe input part; and releasably engaging the second tilt element to thetransfer part.
 4. The method of claim 3, wherein selectively engagingthe transfer part to the input part comprises rotating the input partrelative to the transfer part during rotation of the first tilt elementfor a predetermined range.
 5. The method of claim 4, wherein selectivelyengaging the transfer part to the input part further comprises rotatingthe transfer part via the input part after rotation of the first tiltelement for the predetermined range.
 6. The method of claim 5, whereinreleasably engaging the second tilt element to the transfer partcomprises: engaging the second tilt element to the transfer part with atorsion spring; and releasing engagement of the torsion spring with thetransfer part at each of the two opposite rotational orientations of thesecond tilt element.
 7. The method of claim 1, further comprising:attaching a first cord of a tilt ladder to the first tilt element; andattaching a second cord of the tilt ladder to the second tilt element.8. A method of operating a tilt assembly of a blind, the methodcomprising: rotating a first tilt element of the tilt assembly about adrive axis for operating at least one tilt ladder; delaying rotation ofa second tilt element of the tilt assembly during an initial rotation ofthe first tilt element; and rotating the second tilt element after theinitial rotation of the first tilt element for further operating the atleast one tilt ladder.
 9. The method of claim 8, further comprisingrotating a drive shaft to rotate the first tilt element and the secondtilt element.
 10. The method of claim 9, further comprising: releasablyengaging the first tilt element to the drive shaft; and releasingengagement of the first tilt element to the drive shaft at each of twoopposite rotational orientations of the first tilt element.
 11. Themethod of claim 9, further comprising: releasably engaging the secondtilt element to the drive shaft; and releasing engagement of the secondtilt element to the drive shaft at each of two opposite rotationalorientations of the second tilt element.
 12. The method of claim 11,wherein releasably engaging the second tilt element to the drive shaftcomprises: engaging an input part to the drive shaft; selectivelyengaging a transfer part to the input part; and releasably engaging thesecond tilt element to the transfer part.
 13. The method of claim 12,wherein selectively engaging the transfer part to the input partcomprises rotating the input part relative to the transfer part to delayrotation of the second tilt element.
 14. The method of claim 13, whereinselectively engaging the transfer part to the input part furthercomprises rotating the transfer part via the input part to rotate thesecond tilt element after the initial rotation of the first tiltelement.
 15. The method of claim 14, wherein releasably engaging thesecond tilt element to the transfer part comprises: engaging the secondtilt element to the transfer part with a torsion spring; and releasingengagement of the torsion spring with the transfer part at each of thetwo opposite rotational orientations of the second tilt element.
 16. Themethod of claim 8, further comprising: attaching a first cord of the atleast one tilt ladder to the first tilt element; and attaching a secondcord of the at least one tilt ladder to the second tilt element.
 17. Atilt assembly for a blind, comprising: a rotatable drive shaft; a firsttilt element and a second tilt element rotatable by said drive shaft foroperating at least one tilt ladder; a first clutch mechanism releasablyengaging said first tilt element to said drive shaft; a second clutchmechanism releasably engaging said second tilt element to said driveshaft; and a delay mechanism engaged with said drive shaft and saidsecond tilt element, said delay mechanism configured to transferrotation of said drive shaft to said second tilt element after saidfirst tilt element has begun to rotate.
 18. The tilt assembly of claim17, wherein said delay mechanism comprises: an input part engaged withsaid drive shaft such that said input part rotates with said driveshaft; and a transfer part engaged with said second tilt element;wherein: said input part is configured to rotate relative to saidtransfer part through a predetermined angle before transferring rotationof said drive shaft to said transfer part.
 19. The tilt assembly ofclaim 18, wherein said transfer part is releasably engaged with saidsecond tilt element by said second clutch mechanism.
 20. The tiltassembly of claim 19, wherein said second clutch mechanism is configuredto release engagement of said transfer part with said second tiltelement at each of two opposite rotational orientations of said secondtilt element.